1. Field of the Invention
The present invention relates to a pneumatic tire having circumferentially extending straight main grooves which are arranged asymmetrically about the tire equator to improve wet performance, uneven wear resistance and tire noise.
2. Description of the Related Art
In recent years, in order to improve wet performance especially during high speed running, tread patterns arranged asymmetrical about the tire equator are widely used in passenger car tires, especially high performance sport car tires.
Such asymmetrical tread patterns are disclosed in JA-P-A-1-115705, JA-P-A-3-32906, JA-P-A-7-32822, JA-P-A-3-121912, JA-P-B-5-15562 and JA-P-B-6-57485.
In general, the asymmetrical tread patterns are directionally bound. In other words, the tire has a designed rotational direction. If such tires are incorrectly installed in the reverse direction, the expected performance such as drainage, wet grip and the like can not be obtained and there is a danger of accident caused by slipping. Further, there are actual problems such that two different types of tires for use on the right side and left side of a car have to be prepared in every tire size. Thus two types of tire molds are required, which increases tire manufacturing costs, storage costs and the like.